That seems largely unenforceable... 

Via the Seattle Times: 

Seattle will require gun owners to lock up their firearms, after the City Council voted unanimously Monday to pass legislation proposed by Mayor Jenny Durkan.

Starting 180 days after Durkan signs the legislation, it will be a civil infraction to store a gun without the firearm being secured in a locked container.

The legislation will apply only to guns kept somewhere, rather than those carried by or under the control of their owners.

Also under the legislation, it will be a civil infraction when an owner knows or should know that a minor, “at-risk person” or unauthorized user is likely to access a gun and such a person actually does access the weapon.

The legislation allows fines up to $500 when a gun isn’t locked up, up to $1,000 when a prohibited person accesses a firearm and up to $10,000 when a prohibited person uses the weapon to hurt someone or commit a crime.

“While we can’t prevent every gun death or injury, we can take steps to help prevent future tragedies,” Durkan said in a statement. “Requiring that gun owners responsibly store their guns can help make our communities safer places to live.”

Read more here.